N-methylolsilylethers of ureas and imidazolidinones



United States Patent 3,547,943 N-METHYLQLSILYLETHERS 0F UREAS ANDIMIDAZOLIDINONES Ferdinand Senge, Krefeld, and Herman Schnell,Krefeld-Urdingen, Germany, assignors t0 Farbenfahriken BayerAktiengesellschaft, Leverkusen, Germany, a corporation of Germany NoDrawing. Original application July 11, 1967, Ser. No. 652,413. Dividedand this application June 30, 1969, Ser. No. 837,921

Claims priority, application7gzrmany, July 26, 1966,

49 Int. or. com 103/04, 49/34 U.S. Cl. 260309.7 10 Claims ABSTRACT OFTHE DISCLOSURE N-methylolsilylethers formed by reacting N-methylolcompounds with hexaalkyldisilazanes in a molar ratio of about 1:1 to 1:8at temperatures of -130 C. and their utility in modifying polymericproducts.

It is surprising that the process according to the invention proceeds insuch a simple manner and with good yields.

The N-methylol compounds (I) used as starting materials are known fromthe literature and can be obtained by reacting suitablenitrogen-containing compounds with formaldehyde in an aqueous medium orwith polymeric formaldehyde in an anhydrous medium.

The following compounds may be mentioned as examples of suitableN-methylol compounds for the process of the invention: N-methylolcompounds of aliphatic, aromatic, cycloaliphatic, araliphatic,heterocyclic carboxylic or sulphonic acid amides or carboxylic acidimides. The carboxylic acid or sulphonic acid amides may be substitutedon the amide group by alkyl groups having 1 to 8 C-atoms such asmethyl-ethyl or isopropyl or by aryl groups such as phenyl or naphthyl,and these may in addition contain lower alkyl or halogen substituents.Similarly, the acid radicals on which the carboxylic acid or sulphonicacid amides are based may be substituted by radicals such as halogen, inparticular chlorine, or by nitro groups, alkoxy groups or alkoxycarbonyl groups, etc. The above-mentioned aliphatic or araliphatic acidamides or imides may be linear or branched; they may also containolefinically unsaturated bonds once or a number of times in themolecule. The carboxylic acid and sulphonic acid amides and carboxylicacid imides are derived from the corresponding monoor polybasic acids.

The following are examples of typical N-methylol compounds.N-methylol-acetamide, N-methylol-propionic acid amide,N-methylol-N-methylpropionic acid amide, N- methylol-undecanoic acidamide, N-methylol-stearic acid amide, N-methylol-palmitic acid amide,N-methylol-achloroacetamide, N-methylol-acrylic acid amide,N-methylol-N-phenyl acrylic acid amide, N-methylol-methacrylic acidamide, N-methyloLa-ethyl acrylic acid amide, N- methylol-u-chloroacrylicacid amide, N-methylol-oleic acid amide, N-methylol-sorbic acid amide,N,N-bis-methylol-fumaric acid diamide, N,N-bis-methylol-muconic aciddiamide, N,N'-bis-methylol-adipic acid diamide andN,N'-bis-methylol-sebacic acid diamide; N-methylol-cyclohexanecarboxylicacid amide, N-methylol-cyclopentane-carboxylic acid amide;N-methylol-benzoic acid amide; N-methylol-p-tolyl acid amide,N-methylohnaphthoic acid amide, N-mehtylol-salicylic acid amide, N-methylol-4-hydroxybenzoic acid amide, N-rnethylol-4-tertiary butylbenzoic acid amide, N-methylol-4-chlorobenzoic acid amide,N-methylol-phenylacetic acid amide and N-methy1o1-4-pyridino-carboxylicacid amide; N-methylolmethanesulphonic acid amide,N-methylol-butane-sulphonic acid amide, N-methylol-dodecylsulphonic acidamide, N-methylolbenzene sulphonic acid amide, N-methylol-N-methyltoluenesulphonic acid amide, and N-methylol-cyclohexanesulphonic acid amide; N-methylolmalonic acid imide,N-methylol-maleic acid imide, N- methylol-phthalimide,N-methylol-tetrahydrophthalimide, N-methylol-hexahydrophthalimide andN-methylol-diglycollic acid imide.

Other suitable N-rnethylol compounds are saturated or unsaturatedurethanes or ureas or N-monomethylol to N- hexamethylol compounds ofmelamine. The said classes of compounds may be partly substituted on thenitrogen by alkyl groups having 1 to 4 C-atoms or alkenyl groups having2 to 6 C-atoms or by the butadiene-(l,3)-yl group.

The following compounds may be mentioned as particular examples:N-methylol-carbamic acid esters having 1 to 18 C-atoms in the esteralkyl group, N-methylol-carbamic acid allyl esters (allylurethane),N-monomethylolurea, N,N-bis-methylol-urea, N-rnonomethyl-N-monomethylol-urea, N,N-dimethyl N monomethylol-urea, N,N'-dimethylol N,N'dimethyl-urea, N-monomethylolethylene-urea,N,N-bis-methylol-ethylene-urea, N-vinyl- N-methylol-urea, and N-methylolcompounds of dicyandiamide.

The following compounds are preferred: N-methylolacetamide,N-methylol-acrylic acid amide, N-methylolmethacrylic acid amide,N-methylol-p-toluenesulphonic acid amide, N-methylolsorbic acid amide,N-methylolmaleic acid amide, N-methylol-phthalic acid imide, N-methylol-carbamic acid allyl esters, N-monomethylolurea,N,N-bis-methylol-urea and the monoto hexamethylol compounds of melamine.

The hexaalkyl-disilazane to be used according to the invention whichhave the general formula (R)sESiN-SiE(R)3 it, in which R=alkyl,preferably methyl, R =H or alkyl having 1 to 18 C-atoms,

aryl such as phenyl, which may be substituted by halogen, in particularchlorine or by alkyl groups having 1 to 4 C-atoms, are obtained in knownmanner (see W. Noll Chemie und Technologie der Silikone, Verlag ChemieGmbH., Weinheim, Bergstr. 1960, p. Gmelins Handbuch der Anorg. Chemie,Verlag Chemie GmbH., 1958, 8th edition, volume 15, part C, p. 307) byreacting trialkylmonochlorosilanes with ammonia or primary aliphat- 10or primary aromatic amines.

It -is preferred to use hexamethyldisilazane,N-methylhexamethyldisilazane and N-ethyl hexamethyldisilazane.Hexamethyldisilazane is the most preferred compound.

The N-methylol compounds are reacted with the disilazanes in the molarratio of about 1:1 to 1:8, preferably 1:1.1 to 1:2 at temperatures of 20to 130 C., preferably 40 to 80 C. It is advantageous to carry out thereaction in the presence of catalytic quantities of a catalyst which hasan acid action. The quantities of catalyst are from 0.001 to 2% byweight based on disilazane, preferably 0.01 to 0.5% by weight.

The following compounds are examples of suitable acid catalysts: HCl, H50 H PO butanesulphonic acid, ptoluenesulphonic acid and, preferably,the corresponding ammonium salts.

With very highly reactive N-methylol compounds, the reaction can also becarried out without catalysts although the reaction then generallyproceeds considerably more slowly and only at higher temperatures. Thismay lead to deleterious side reactions such as autocondensation of themethylol compounds. In the case of compounds that are less sensitive tocondensation, one can also successfully use catalytic quantities of thefree acid.

The process according to the invention can be carried out in bulk or inan organic solvent. Suitable solvents include, for example,dimethylsulphoxide, methyl acetate, ethyl acetate, dioxane andtetrahydrofuran. For preference, ethyl acetate or methyl acetate isused.

The process itself may be carried out by mixing the methylol compoundwith the hexaalkyldisilazane and, where used, the acid catalyst and/or asolvent and heating the mixture to the reaction temperature, whenliberation of ammonia or of the amine from which the hexaalkyldisilazaneis derived takes place. After the reaction is complete, the product isworked up by distillation or crystallisation. Alternatively, thereaction may be carried out by adding the methylol compound to the otherreactants either continuously or discontinuously.

A preferred method of preparing the N-methylolsilyl ethers according tothe invention consists in reacting the N-methylol compounds withhexamethyldisilazane in a molar ratio of 1:1.1-2 in the presence ofcatalytic quantities of (NH SO., at 40 to 80 C. with the exclusion ofmoisture and with stirring. After only a short time the reaction becomesevident by vigorous evolution of ammonia. When the evolution of gas hasdied down, stirring is continued for another to minutes and the excesshexamethyldisilazane is drawn oif. For many purposes, theN-methylolsilyl ether obtained in this way is sufliciently pure.

Other disilazanes and different proportions of reactant catalysts ororganic solvents may be used and different temperatures may be employed.

If it is desired to prepare the methylolsilyl ethers by reacting alkylmonochlorosilanes with N-methylol compounds, the presence ofstoichiometric quantities of HCl acceptors such as pyridine or othertertiary amines is necessary. The hydrochloride produced in largequantities in this reaction, however, renders working up diflicult andeasily cause undesired side reactions.

These disadvantages can be obviated by the process according to theinvention.

N-methylolsilyl ethers prepared according to the invention are valuableintermediate products for medicaments, textile auxiliary agents andsynthetic resins.

The N-rnethylolsilyl ethers are capable of reacting with other reactivegroups, e.g., hydroxyl groups, carboxyl groups, amino groups, even undermild conditions. Therefore, the N-methylolsilyl ethers are useful formodifying polymers and polycondensation products containing theabovesaid groups, e.g., for hydrophobing cellulose and partial celluloseesters as well as for crease-proofing cotton.

Bior polyfunctional N-methylolsilyl ethers as well as the disilyl etherof N,N'-dirnethylol adipic acid diamide react with hydroxylgroup-containing macromolecules with cross-linking. Therefore, they canbe used as cross-linking agents in lacquer binders having incorporatedhydroxyl groups.

EXAMPLE 1 10 g. (0.112 mol) of N-methylolacetamide, 9 g. (0.056 mol) ofhexamethyldisilazane and 0.01 g. of sulphuric acid are heated to 70 to75 C. with stirring and exclusion of moisture. After a short time, briskliberation of ammonia begins and this is complete after about 10minutes. The solution is diluted with about 50 ml. of petroleum ether,filtered, and the solvent is drawn off. The residue is fractionatedusing an oil pump.

Yield: 13 g. (0.086 mol) =71.8% by weight of the theoretical.

B.P. 60-61 C. 1 :0962. n =1.4361.

C H O NSi (161.248).Calculated (percent): C, 44.69; H, 9.38; N, 8.69;Si, 17.42. Found (percent): C, 44.42; H, 9.17; N, 9.02; Si, 17.10.

EXAMPLE 2 In a manner analogous to Example 1, 9 g. (0.044 mol) ofN,N'-dimethylol-adipic acid diamide are reacted with 17.1 g. (0.1 mol)of hexamethyldisilazane. About 35 ml. of benzene are added to theresulting solution, the solution is filtered and the solvent is drawnofl. The residue is recrystallised from methyl acetate.

Yield: 10 g. (0.0287 mol)=65.4% by weight of theoretical.

Melting point: 75-75.5 C.

C H O N Si (348.606).Calculated (percent): C, 48.24; H, 9.25; N, 8.04;Si, 16.12. Found (percent): C, 48.52; H, 8.93; N, 8.24; Si, 16.15.

EXAMPLE 3 29.5 g. (0.2 mol) of N,N-dimethylolurea, 40 g. (10.25 mol) ofhexamethyldisilazane, 29 g. of dimethylsulphoxide and 0.1 g. of (NH SOare heated to to C. with stirring and exclusion of moisture. After ashort time, brisk evolution of ammonia begins and this is complete afterabout 10 minutes. The solution is diluted with about 50 ml. of petroleumether, filtered, and cooled with ice. The precipitated product isseparated by suction filtration, dried, and recrystallised from ligroin.

Yield: 44 g. (0.1505 mol)=% by weight of theoretical. Melting point: 158C. (with decomposition).

EXAMPLE 4 In a manner analogous to Example 1, 24 g. (0.202 mol) ofN-methylol-carbamic acid ethyl ester and 18.5 g. (0.115 mol) ofhexamethylidsilazane are reacted at 55 to 50 C. in the presence of 0.01g. of sulphuric acid (conc.). When the reaction is complete, the productis removed by suction filtration and fractionated using an oil pump.

Yield: 20 g. (0.091 mo1)=45.5% by weight of theoretical.

C7H17O3NSi (molecular Weight, 191.311).-Calculated (percent): C, 43.95;H, 8.95; N, 7.32; Si, 14.68. Found (percent): C, 44.16; H, 8.71; N,7.16; Si, 14.27.

EXAMPLE 5 In a manner analogous to Example 1, 6.5 g. (0.05 mol) ofN-methylol-sorbic acid amide and 5 g. (0.031 mol) ofhexamethyldisilazane are reacted together in the presence of 0.01 g. ofsulphuric acid (conc.). When the re action is complete, 20 ml. ofpetroleum ether are added, the reaction mixture is filtered, thefiltrate is cooled and the precipitated product is separated by suctionfiltration and dried.

Yield: 5 g. (0.0228 mol)=47.5% by weight of the theoretical.

Melting point: 79-80" C.

C H NO Si (213.36).Calculatecl (percent): 56.29; Si, 13.16. Found(percent): C, 56.29; Si, 13.00.

EXAMPLE 6 In a manner analogous to Example 1, 5 g. (0.0226 mol) ofN-methylol-phthalimide and 2 g. (0.0124 mol) of hexamethyldisilazane and0.1 g. of NH Cl are boiled under reflux at 120-130" C. When the reactionis complete, petroleum ether is added, the reaction mixture is filtered,the filtrate is cooled with ice, and the precipitated product isseparated by suction filtration and dried.

Yield: 3.5 g. (0.01408 mo1)=62% by weight of theoretical.

Melting point: 6263 C.

C H O NSi (249.35 ).Calculated (percent): C, 57.71; H, 6.06; N, 5.62;Si, 11.26. Found (percent): C, 57.79; H, 5.95; N, 5.70; Si, 10.91.

EXAMPLE 7 20 g. (0.198 mol) of N-methylolacrylamide, 18 g. (0.112 mol)of hexamethyldisilazane, 25 ml. of methyl acetate, 0.1 g. of (NH SO and0.01 g. of phenothiazine are reacted together at 30 to 40 C. in a manneranalogous to Example 1. The solvent is evaporated ofl? and the residueis distilled using an oil pump.

Yield: 29.5 g. (0.17 mol)==85% by weight of theoretical.

C7H 5O NSi (173.295 ).-Calculated (percent): C, 48.52; H, 8.72; N, 8.08;Si, 16.21. Found (percent): C, 48.53; H, 8.53; N, 8.34; Si, 16.02.

EXAMPLE 8 In a manner analogous to Example 7, 300 g. (2.6 mol) ofN-methylol-methacrylic acid amide, 240 g. (1.5 mol) ofhexamethyldisilazane, and 0.1 g. of (NH SO are reacted at 40 C. in thepresence of 250 ml. of ethyl acetate and 0.01 g. of phenothiazine andworked up.

Yield: 469 g. (2.5 mo1)=96% by weight of theoretical.

B.P. 7779 C. Melting point: 31-32 C.

C H O NSi (187.20).-Calculated (percent): C, 51.26; H, 9.16; N, 7.48;Si, 14.95. Found (percent): C, 50.66; H, 9.29; N, 7.46; Si, 14.73.

If 50 g. (0.045 mol) of N-methylol-methacrylic acid amide and 45 g.(0.26 mol) of N-methyl-hexamethyldisilazane are reacted under theconditions of Example 8 there are obtained 61 g. (0.33 mo1)=73% byweight of methacrylic acid amide-N-methylol-trimethylsilyl ether.

Melting point 3l32 C.

EXAMPLE 9 In a manner analogous to Example 1, 3 g. (0.015 mol) ofN-rnethylol-p-toluenesulphonic acid amide and 1.75 g. (0.008 mol) ofhexamethyldisilazane are reacted together at 75 to 80 C. in the presenceof 0.01 g. of sulphuric acid (cone). When the reaction is complete,petroleum ether is added and the reaction mixture is filtered.

The filtrate is cooled and the precipitated product is separated bysuction filtration and recrystallised.

Yield: 3 g. (0.011 mol)=73.5% by weight of theoretical.

Melting point: 70.5-71.5 C.

C H O NSi (273.417).Calculated (percent): C, 48.32; H, 7.00; N, 5.12;Si, 10.27. Found (percent): C, 48.48; H, 6.45; N, 5.30; Si, 10.21.

EXAMPLE In a manner analogous to Example 1, 23 g. (0.17 mol) ofN-methylol-carbamic acid allyl ester in g. of ethyl acetate are reactedwith 15 g. (0.09 mol) of hexamethyl disilazane at 80-85 C. withinminutes and worked up.

6 EXAMPLE 11 21.5 g. (approximately 0.1 mol) of a methylolrnelaminecompound prepared from formaldehyde and melamine and containing aboutthree methylol groups were dissolved in 50 ml. of dimethylsulphoxide andreacted with 30 g. (0.19 mol) of hexamethyldisilazane at 60-70 C. within15 minutes. The solvent was drawn off and the residue was dissolved inethyl acetate and precipitated from petroleum ether.

Yield: 34 g. (0.079 mol):79% by weight of the theoretical.

The product had a Si content of 18.4%, which corresponds to a degree ofsubstitution of the methylol groups of 95% EXAMPLE 12 In a manneranalogous to Example 1, 15 g. (0.1 mol) of nicotinic acid amide arereacted with 12 g. (0.06 mol) of hexamethyldisilazane at about 80 C.within 10 minutes. The product was recrystallised from petroleum ether.

Yield: 17 g. (0.07 mol)=76% by Weight of the theoretical.

Melting point: 74-74.5 C.

C1QH16N202S1. (224.344).Calculated (percent): C, 53.54; N, 12.49; Si,12.52. Found (percent): C, 54.10; N, 12.40; Si, 12.60.

EXAMPLE 13 In a manner analogous to Example 1, 10 g. (0.064 mol) ofN-methylolhexahydrobenzoic acid amide are reacted with 9 g. (0.05 mol)of hexamethyldisilazane at 60 C.

Yield: 10.5 g. (0.044 mol)=69% by weight of theoretical.

Melting point: 7172 C.

C H NO Si (228.4l1).-Ca1culated (percent): C, 57.99; H, 10.57; N, 6.13.Found (percent): C, 57.25: H. 9.84; N, 6.38.

EXAMPLE 14 In a manner analogous to Example 1, 13 g. (0.1 mol) ofN-methylol-p-chlorobenzoic acid amide are reacted with 12 g. (0.75 mol)of hexamethyldisilazane at 110 C.

Yield: 11 g. (0.043 mol)=43% by weight of theoretical.

Melting point: -91 C.

C H ClNO Si (257.S04).Calculated (percent): C, 51.34; H, 6.27; N, 5.44.Found (percent): C, 51.52; H, 6.24; N, 5.42.

EXAMPLE 15 In a manner analogous to Example 1, 16.5 g. (0.1 mol) ofN-methylolphenylacetic acid amide are reacted with 12 g. (0.075 mol) ofhexamethyldisilazane at 6070 C.

Yield: 12 g. (0.51 mol)=51% by weight of theoretical.

Melting point: 4142 C.

C H NO Si (237.364).-Calcu1ated (percent): C, 60.73; H, 8.11; N, 5.90.Found (percent): C, 60.69; H, 7.75; N, 6.10.

EXAMPLE 16 10 parts by weight of N-trimethyl siloxymethylmethacrylamide, 30 parts by Weight of methyl methacrylate are mixed with45 parts by weight of xylene. After addition of 0.4 part by weight ofazodiisobutyrodinitrile and 0.3 part by weight ofditert.-dodecylmercaptan as regulator polymerization was carried out at70 C. during 6.5 hours. The copolymer obtained has a relative viscosityof 1.1953 measured with an Oswald viscosimeter at 25 C. and at aconcentration of 10 -g./litre in benzene.

Demonstration of conversion of the soluble copolymer into insolublecross-linked product: 0.22 ml. of

solution is added to 20 g. of a 25% by Weight solution in xylene/butanol(11:1) of the copolymer obtained. The mixture becomes cloudy after only10 minutes, a gellike product being formed, accompanied bycross-linking.

7 A film of the copolymer which is stoved for 30 minutes 4. The compoundof claim 3 wherein each R is methyl; at 150 C. is insoluble in Xyleneand has a gel-content 5. The compound of the first formula of claim 1'of almost 100%. wherein R is We claim: w R 1. A compound selected fromthe group consisting of 5 CH O I R R R CH 0 R P h and each R" ishydrogen. 6. The compound of claim wherein each R is methyl. R R R 7.The compound of the second formula of claim 1 and wherein R'" ishydrogen.

8. The compound of claim 7 wherein each R is methyl. (3H2 9. Thecompound of the second formula of claim 1. RN N-CH2-OSi-R wherein R" isH I O -CH20-Si-R wherein R is alkyl, R is hydrogen or 1 I R 10. Thecompound of claim 9 wherein each R is methyl. OH O sil R ReferencesCited R UNITED STATES PATENTS wherein R is also alkyl, each R" ishydrogen, alkyl of 1 to 3,049, 559 3/1962 Montgomery 2 4 carbon atoms,alkenyl of 2 to 6' carbon atoms or buta- 3,172,374 3/1965 Klebe 2 4 '2diene-(1,3)-yl and R" is hydrogen, alkyl of 1 to 4 carbon 3,208,9719/1965 Gilk et a1 260 448'2X atoms, alkenyl of 2 to 6 carbon atoms,butadiene-( l,3)-yl 3 243 429 3 19 Ham 2 44 2 0f 3,278,484 10/1966Tesoro 260448.2X R 3,346,609 10/1967 Klebe 260-4482 3,440,261 4/1969Saam 260-4482 R TOBIAS E. LEVOW, Primary Examiner wherein Ris alsoalkyl. W. F. W. BELLAMY, Assistant Examiner 2. The compound of claim 1wherein each R is methyl. 3. The compound of the first formula of claim1 where- U8. Cl. X.R.

in each R" is hydrogen. 260448. 8, 46.5

